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Scano G - - 1982
In 10 exercising patients with chronic obstructive lung disease (COLD) we measured ventilation (VE), end-tidal CO2 (PETCO2), mean inspiratory flow (VT/TI), the ratio of inspiratory time to total time for one cycle (TI/TTOT), and occlusion pressure at 0.1 s measured at the mouth (P O.1), when they breathed room air ...
Kohl J - - 1982
The contribution of pulmonary stretch receptor (SR) activity to the changes in breathing pattern (f, VT, tI, tE, tI: tE) following inhalation of ammonia vapour has been studied in rabbits at three levels of lung distension, i.e., three levels of SR activity, and during reversible SO2-blockade of SR. The result ...
Nye P C - - 1981
In bilaterally vagotomized, decerebrate or pentobarbitone anaesthetized cats, intense carotid body discharge (FET O2 ca. 0.075) was abruptly removed by injections centrally of 100% O2-equilibrated Ringer into both external carotid arteries. In an inspiration the injections usually shortened that inspiration, reduced its volume and prolonged the immediately following expiration. Early ...
Szlyk P C - - 1981
We analyzed the time courses of the VE, VT, and f responses to graded levels of exercise produced by increases in treadmill speed at preset inclines in 207 experiments on 15 tracheostomized dogs. At the onset of work, VE increased within 1-2 respiratory cycles (VE fast), and then either remained ...
Schuhmann R E - - 1981
A transient time-dependent increase in tidal volume (TV) and respiratory rate has been observed as a spirometric loading effect in experiments on 22 decerebrate cats. Respiration was recorded via the impedance pneumograph throughout the entire experiment while tidal volume was measured at intervals of 10-60 min on a spirometer. A ...
Slutsky A S - - 1981
Recent studies have shown that effective pulmonary ventilation is possible with tidal volumes (VT) less than the anatomic dead-space if the oscillatory frequency (f) is sufficiently large. We systematically studied the effect on pulmonary CO2 elimination (VCO2) of varying f (2-30 Hz) and VT (1-7 ml/kg) as well as lung ...
Gilbert R - - 1981
Although rib cage (RC) and abdomen (Ab) motion is believed to reflect intercostal and diaphragm contributions to breathing, systematic investigations have failed to confirm this. We measured inspiratory changes in RC and Ab anterior-posterior diameter (delta RC and delta Ab) both corrected for volume equivalence (isovolume) and not corrected (isodistance, ...
Leite-de-Barros-Neto T - - 1981
1. It has been previously shown that Ketalar-anesthetized dogs do not exhibit alterations either in ventilation or in oxygen uptake during passive motion. In the present study, the same model was used to study the effects induced by increasing extracellular K+ to the concentration achieved during active exercise. 2. The ...
Kelsen S G - - 1981
The effects of resistive loads applied at the mouth were compared to the effects of bronchospasm on ventilation, respiratory muscle force (occlusion pressure), and respiratory sensations in 6 normal and 11 asthmatic subjects breathing 100% O2. External resistive loads ranging from 0.65 to 13.33 cm H2O/liter per s were applied ...
Merrick J - - 1981
Three indexes of inspiratory muscle function were evaluated in 20 healthy young adults before and after a six-week program of diaphragmatic breathing exercises. Thrice weekly, each subject performed 30 maximal voluntary diaphragmatic contractions in the supine position with a moderately heavy weight (range: 7-23 kg, or 15.4-50.7 lb) placed on ...
Pardy R L - - 1981
Using a simple, inexpensive, at-home program, 12 patients with moderate-to-severe chronic air flow limitation trained their inspiratory muscles. All showed increased inspiratory muscle endurance with no change in inspiratory muscle strength. Seven of the twelve patients increased their endurance time for submaximal exercise beyond the 90% confidence limits determined by ...
Van Meerhaeghe A - - 1981
Ventilation was analysed during a maximal and progressive exercise in 12 patients suffering from interstitial lung disease (ILD) and in 15 healthy subjects. "Rapid shallowing breathing" pattern was observed in patients with ILD. Both normals and patients showed a linear relationship between VE, VT/TI (mean inspiratory flow) and VCO2. The ...
Bosisio E - - 1981
We studied the ventilatory response to an isometric handgrip (50% maximum voluntary contraction) in 7 young normal subjects. VE increased significantly during isometric contraction due to increases in Vt/Ti (the mean inspiratory flow) and Ti/Ttot (the timing component of ventilation). The increase in Vt/Ti is greater than that in Ti/Ttot; ...
Burki N K - - 1981
To examine the effects of continuously added background inspiratory loads on the difference thresholds for resistive (delta R50) and elastic load detection (delta E50), 12 healthy subjects were studied. The results showed that, whereas the addition of a constant background elastic load significantly altered delta R50, the addition of a ...
Martin B J - - 1981
Ventilation (VE) climbs steadily throughout prolonged heavy exercise. While this VE "drift" has implications for the adequacy of gas exchange in long-term exercise, its mechanism remains unknown. We examined the behavior of previously proposed mediators of VE drift during one hour of cycle ergometer exercise at constant work rate requiring ...
Jensen J I - - 1980
1. The extent to which the pattern of breathing at maximal ventilation in man is affected by the mechanical properties of the respiratory pump has been studied. 2. The maximal effort flow volume (MEFV) loop has been used to calculate the shortest possible inspiratory (TI) and expiratory (TE) durations associated ...
Byrick R J - - 1980
The effects of respiratory waveform on rebreathing in a modified Mapleson D circuit were studied in 18 healthy adult patients anesthetized with either enflurane or halothane. At high fresh gas flow (FGF) rate, when no rebreathing of CO2 occurred, the duration of inspiration (Ti) with enflurane was 41 per cent ...
Lopata M - - 1980
The effects of external elastic loading (EL) (19 cmH2O/l), applied continuously (C) and intermittently (I) during CO2 rebreathing, on diaphragmatic electromyogram (EMGdi), mouth occlusion pressure (P0.15), and ventilation (VI) were studied in normal subjects. EMGdi was analyzed as moving time average and quantitated in terms of peak (mean p) and ...
Stubbing D G - - 1980
A body plethysmograph was used to measure pulmonary mechanics in six subjects with chronic airflow obstruction during steady states at rest and during exercise at 200 and 400 kpm . min-1. The mean forced expired volume in 1 s was 1.32 liters (39.2% predicted). The flow rates during tidal breathing ...
Gabrielsen J - - 1980
Rebreathing in the Mapleson D system with a varying fresh gas flow (FGF) was measured during an experimental set-up, which consisted of a compliance lung delivering the exhaled gases with the same, fixed concentration throughout the experiment, a commercially available Bain's system and a respirator. While changes in compliance, airway ...
Gal T J - - 1980
Diaphragmatic function estimated by transdiaphragmatic pressure (Pdi) was studied in eight normal subjects during progressive partial paralysis with d-tubocurarine (dTc). Dynamic Pdi was measured during quiet tidal breathing, maximum deep inspiration, and 12-s maximum voluntary ventilation (MVV). Maximum static transdiaphragmatic pressure (Pdimax) was also measured during maximum static inspiratory efforts ...
Cotton E K - - 1980
The respiratory responses to acute hypoxia were investigated in 21 newborn infants in Leadville, CO. Time-related changes in pulmonary ventilation (VE) described four distinct phases to the hypoxic response characterized by an abrupt initial decrease (phase I), a transient subsequent increase (phase II) and decrease (phase III), and a further ...
Gross D - - 1980
The diaphragmatic electromyogram was used to detect fatigue of the diaphragm in six chronic quadriplegics while they breathed for 10 minutes against a variety of inspiratory resistances. The maximum static inspiratory mouth pressure was measured at functional residual capacity (Pmmax) and from the electromyogram the critical inspiratory mouth pressure that ...
Lopata M - - 1980
The effects of inspiratory flow resistance on mouth occlusion pressure (P0.15) and diaphragmatic EMG (EMGdi) responses to CO2 rebreathing were studied in normal subjects. Occlusion pressures were measured 150 msec after onset of an inspiratory effect; EMGdi was analyzed as a moving time average and quantified in terms of peak ...
Martin B J - - 1979
Passive elevation of the body core temperature (Tc) induces rapid, shallow breathing in resting man. We wondered if exercise-induced Tc elevation would also lead to decreased tidal volume (VT) and increased breathing frequency (f) during exercise. To investigate this question, 10 subjects each performed 47 min of cycle ergometer exercise ...
Macklem P T - - 1979
During Mueller maneuvers (MM), the volume change of rib cage, delta Vrc, and abdomen, delta Vab, are equal and opposite. Thus delta Vrc = -delta Vab. Substituting delta Prc.Crc for delta Vrc and delta Pab.Cab for delta Vab yields: delta Prc = - delta Pab.Cab/Crc, where delta Prc, delta Pab, ...
Chaudhary B A - - 1979
The pattern of ventilation (consisting of tidal volume, frequency of breathing, minute ventilation, peak inspiratory flow rate, inspiratory time, mean inspiratory flow rate, and inspiatory time ratio) and pulmonary function tests (consisting of spirometry, lung volumes, and airway resistance) were measured in ten conscious, healthy subjects before and after anesthesia ...
Thalmann E D - - 1979
The effects of static lung loading in the range +20 cmH2O to -20 cmH2O was investigated in 3 male subjects breathing air during submerged exercise in the prone position at pressures ranging from 1.45 ATA to 6.76 ATA. Both maximal and submaximal exercise was performed and dry controls were done ...
Bechbache R R - - 1979
1. The pattern of breathing, defined as the relations between tidal volume and inspiratory and expiratory times, was measured during the stimulation of breathing by carbon dioxide (hyperoxic rebreathing at rest) in twenty-seven healthy, young volunteers. 2. Most of the patterns (twenty) were divisible into two parts, for low (range ...
Bouverot P - - 1979
Three varieties of birds (a non-flyer, the chicken; a diver, the duck; a flyer, the pigeon) were studied in resting conditions at neutral ambient temperature, while awake, either intact or sham operated, or after bilateral chronic carotid body denervation. Tidal volume (VT), ventilatory period (T) and minute volume (V = ...
Askanazi J - - 1979
Ventilatory patterns during rest, CO2 inhalation (2, 3, and 4%) and three levels of exercise were analyzed in supine men using a canopy system for noninvasive measurements. Changes in tidal volume (VT) and breathing frequency (f) with equal increases in minute ventilation (VE) differed significantly during exercise and CO2 inhalation. ...
Feisal K A - - 1979
Pulmonary function was examined in 19 young asthmatic patients at rest and during two levels of excercise. Findings at rest included decreased flow rates, increased residual volume, normal minute (VE) and alveolar (VA) ventilation, increased ratio of physiological dead space to tidal volume (VD/VT), increased alveolar-arterial oxygen tension difference (A-a ...
Agostoni E - - 1979
Decay rate of inspiratory muscle pressure (PmusI) was studied in 4 subjects during post-inspiratory period of zero flow (TEz) occurring under discontinuous inspiratory elastic load (DIL). End-inspiratory pressure (PmuseI) was increased by dead spaces or exercises. Decay rate was related to PmuseI by a power function with exponent greater than ...
Ward S A - - 1979
Breath-by-breath respiratory responses of three healthy adults to imposed alternate-breath oscillation of end-tidal PCO2 (between +5 and +15 torr above the eupnoeic level) and/or PO2 (between 80 and 45 torr) were studied at rest and during mild cycle ergometer exercise. There was often alternation in inspiratory and expiratory tidal volumes ...
Askanazi J - - 1979
Acutely ill patients commonly increase minute ventilation (V) to varying degrees. The pattern of breathing utilized to increase V was analyzed in normal subjects and acutely ill surgical patients. V = tidal volume (VT) x frequency (f), or V = inspiratory flow x (TI/TTOT, inspiratory time/total cycle time). CO2 inhalation ...
Martin B J - - 1979
In progressive exercise increased tidal volume (VT) accompanies increased ventilation (VE) until a VT plateau is reached. We observed in 13 subjects a correspondence between the arrival of the VT plateau and the anaerobic threshold (AT). To examine this association between a mechanical event (the VT plateau) and a metabolic ...
Vellody V P - - 1978
With a linearized respiratory magnetometer, measurements of anteroposterior and lateral diameters of both the rib cage and the abdomen were made at functional residual capacity and continuously during tidal breathing. Twenty-five subjects with normal respiratory systems were studied in the sitting, supine, lateral decubitus, and prone body positions. When subjects ...
Borison H L - - 1978
Arterial blood pH (pHa) was continuously monitored in decerebrate or pentobarbital-anesthetized cats with a rapidly responding hydrogen ion sensor inserted into the aorta. Alveolar carbon dioxide partial pressure and pHa were controlled independently during infusions of 1 N NaHCO3 or 0.5 N HCl into the inferior vena cava. Shifts in ...
Garrard C S - - 1978
1. The pattern of breathing expressed as the relationship between tidal volume and the components of breath interval was studied in normal subjects during CO2 rebreathing, both under unloaded conditions and following the introduction of a non-elastic expiratory resistance. 2. Under unloaded conditions end-expiratory thoracic gas volume (FRC) measured plethysmographically ...
Adams J M - - 1978
The interaction of medullary and carotid chemoreceptors during mild stimulation was investigated in 44 experiments on 6 chloralose-urethane anesthetized mongrel dogs using a donor-perfused, bilateral carotid sinus preparation. The donor dog breathed hypoxic mixtures (average PaO2 of 78 mm Hg) and the experimental animal breathed hypercapnic mixtures (average PACO2 of ...
Adams J M - - 1978
We have investigated the respiratory control system with the hypothesis that, although many variables such as minute ventilation (VI), tidal volume (VT), breathing period (TT), inspiratory duration (TI), and expiratory duration (TE) may be observed, the controller functions more simply by manipulating only 2 or 3 of these. Thus, if ...
Wood L D - - 1978
Transpulmonary pressure, lung volume, and flow rate were recorded in two healthy subjects performing graded exercise between 1 and 10 ATA. At simulated depths greater than 4 ATA, exercise was terminated by severe choking dyspnea at levels of work, oxygen consumption, heart rate, and ventilation significantly lower than during maximum ...
Schaanning J - - 1978
Respiratory cycle time components during rest and graded exercise were measured in 18 patients with chronic obstructive lung disease, and compared with controls matched for sex and age. For a given exercise level (50 W) increased minute ventilation was present in the patients. This was due to shorter cycle time. ...
Mortola J P - - 1978
1. We have studied the motion of the abdomen and the rib cage in patients with a transection of the lower cervical spinal cord during normal breathing both in the supine and sitting posture, and compared it with that of normal subjects. 2. In the supine posture the rib cage ...
Gardner W N - - 1977
1. Ambiguities and discrepancies in the published descriptions of the patterns of breathing in man have been re-investigated.Steady-state hyperpnoea during rest was induced in normal subjects of both sexes by means of CO(2) inhalation, usually in high O(2), but sometimes in low (P(A, O2) approximately 200 and 55 torr respectively).2. ...
Cunningham D J - - 1977
1. Quantitative data on the pattern of breathing in normal men and women (Gardner, 1977) have been used to derive expressions that are based on known physiological mechanisms.2. The relations between the applied chemical drive to breathing (expressed as DeltaP(A, CO2) in high O(2)) and the several components of the ...
Grunstein M M - - 1977
In seven anesthetized tracheotomized cats we studied the acute respiratory effects of SO2 inhalation at different steady-state levels of arterial CO2 tension (Paco2). During room air breathing, SO2 (0.05%) addition caused a progressive reduction in tidal volume (VT) and increases in both respiratory frequency (f) and pulmonary resistance (RL). Atropine ...
Lawson E E - - 1977
During acute progressive asphyxia an abrupt transition occurs from regular respiratory efforts to primary apnea and gasping. To study this transition we measured inspiratory duration (TI), expiratory duration (TE), maximal inspiratory tracheal pressure (Pmax), electromyographic activity (EMG) of different muscle groups, and the electrocorticogram (ECoG) of 3- to 5-day-old rabbits ...
Kindl M - - 1977
To treat obesity effectively, a multifaceted approach is needed. This article describes a program for women involving exercise, diet counselling and group interaction.
Agostoni E - - 1977
In anesthetized subjects rib cage strapping (RCS) did not change tidal volume (VT) and increased ventilation (V), whereas abdomen strapping (AS) markedly decreased VT and V. Both kinds of strapping decreased expiratory duration (TE), but did not change inspiratory duration (TI) and breathing rate. RCS and AS decreased lung volume ...
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